Spinal disc prostheses

Abstract

A spine disc prosthesis mimics a natural human spine disc through use of a structure that duplicates a natural Annulus Fibrosis of the disc to provide translation, extension, flexion, and axial support in like manner to a natural disc. The present spine disc prosthesis achieves this through the use of a first and second disk connected to one another via a flexible annulus fibrosis structure. The flexible annulus fibrosis structure or core is characterized by a plurality of compressible (pliant) strands that are affixed to and extend between the first and second disks. The strands are preferably, but not necessarily, situated on and extend about an outer perimeter of inside surfaces of the two end disks so as to mimic natural contours of an annulus fibrosis of a natural spinal disc. The strands may be formed by various types of biocompatible fibers, braids, cords, bundles or the like and may have a hollow core or a solid core (e.g. PEEK [polyetheretherketone] cores/core strands may also be used). The strands may be situated on the vertical, crossed or in other configurations. The end disks may be formed as to promote fusion with adjoining vertebrae when implanted. The end plate may also include a keel and/or installation structure to allow for implanting the spine disc prosthesis.

What is claimed is: 
     
       1. A spinal disc prosthesis comprising:
 a first end disk having a ring and a plurality of rods, the ring having an upper surface, a lower surface, and an inner surface defining an elliptical opening, the plurality of rods extending between and connecting sides of the inner surface of the ring; 
 a second end disk having a ring and a plurality of rods, the ring having an upper surface, a lower surface, and an inner surface, the plurality of rods extending between and connecting sides of the inner surface of the ring; and 
 a flexible core connected to and extending between the first disk and second end disk, the flexible core formed by a plurality of flexible strands extending between and coupling the ring of the first disk and the ring of the second disk; 
 wherein the plurality of resilient strands exclusively provide the translation, extension, flexion, and axial support for the first end disk and the second end disk. 
 
     
     
       2. The spinal disc prosthesis of  claim 1 , wherein the plurality of rods on the first end disk spaced-apart and substantially parallel and the plurality of rods on the second end disk are spaced-apart and substantially parallel. 
     
     
       3. The spinal disc prosthesis of  claim 2 , wherein each one of the plurality of flexible strands is formed of a single fiber. 
     
     
       4. The spinal disc prosthesis of  claim 2 , wherein each one of the plurality of flexible strands is formed of a plurality of twisted fibers. 
     
     
       5. The spinal disc prosthesis of  claim 4 , wherein each one of the plurality of flexible strands includes a core. 
     
     
       6. The spinal disc prosthesis of  claim 5 , wherein the core is comprised of PEEK. 
     
     
       7. The spinal disc prosthesis of  claim 1 , wherein:
 the first end disk is defined by a first frame; and 
 the second end disk is defined by a second frame. 
 
     
     
       8. The spinal disc prosthesis of  claim 7 , wherein:
 the first frame has a first open interior; 
 the second frame has a second open interior. 
 
     
     
       9. The spinal disc prosthesis of  claim 8 , wherein the first plurality of rods provide a first grillwork extending across the first open interior, and the second plurality of rods provide a second grillwork extending across the second open interior; and
 wherein the flexible core extends between the lower surface of the first disk and the upper surface of the second end disk. 
 
     
     
       10. An artificial spinal disc comprising:
 a first end disk having a ring and a plurality of rods, the ring having an inner surface, the plurality of rods connecting and extending between sides of the inner surface of the ring; 
 a second end disk having a ring and a plurality of rods, the ring having an inner surface, the plurality of rods connecting and extending between sides of the inner surface of the ring; and 
 a plurality of resilient strands connecting and extending between the first end disk and the second end disk and situated to form an outline of a natural annulus fibrosis of a natural spine disc within the diameter of the first and second end disks, wherein the plurality of flexible strands define an open interior between the first and second end disks, wherein the plurality of resilient strands exclusively provide the translation, extension, flexion, and axial support for the first end disk and the second end disk. 
 
     
     
       11. The artificial spinal disc of  claim 10 , wherein each one of the plurality of flexible strands is formed of a single fiber. 
     
     
       12. The artificial spinal disc of  claim 10 , wherein each one of the plurality of flexible strands includes a core. 
     
     
       13. The artificial spinal disc of  claim 12 , wherein the core is comprised of PEEK. 
     
     
       14. The artificial spinal disc of  claim 10 , wherein the plurality of fibers are configured as open-cored. 
     
     
       15. The artificial spinal disc of  claim 10 , wherein the plurality of flexible strands extends generally transverse to the first and second end disks. 
     
     
       16. The artificial spinal disc of  claim 10 , wherein the plurality of flexible strands extend in a generally skew manner relative to the first and second end disks. 
     
     
       17. The artificial spinal disc of  claim 10 , wherein the plurality of rods of the first end disk extend through the ring of the first end disk. 
     
     
       18. The artificial spinal disc of  claim 10 , wherein:
 the ring of the first end disk has a first open interior; 
 the ring of the second end disk has a second open interior. 
 
     
     
       19. The artificial spinal disc of  claim 18 , wherein:
 the ring of the first disk is a continuous annular structure; and 
 the ring of the second disk is a continuous annular structure. 
 
     
     
       20. A prosthetic spinal disc comprising:
 a first ovoid ring supporting a first grill structure formed by a plurality of spaced-apart, substantially parallel rods connecting and extending through opposing sides of inner surfaces of the first ovoid ring; 
 a second ovoid ring supporting a second grill structure formed by a plurality of spaced-apart, substantially parallel rods connecting and extending through opposing sides of inner surfaces of the second ovoid ring; and 
 a flexible mesh extending between and connecting the first and second ovoid ends and contoured in a line duplicating a natural Annulus Fibrosis of a natural human spinal disc, the flexible mesh including a plurality of separate adjacent resilient strands connecting and extending between a lower surface of the first ovoid ring and an upper surface of the second ovoid ring, wherein the plurality of resilient strands exclusively provide the translation, extension, flexion, and axial support for the first and second ovoid rings. 
 
     
     
       21. The prosthetic spinal disc of  claim 20 , wherein the flexible mesh is formed of a plurality of flexible strands. 
     
     
       22. The prosthetic spinal disc of  claim 21 , wherein the plurality of flexible strands are formed of a plurality of twisted fibers. 
     
     
       23. The prosthetic spinal disc of  claim 20 , wherein the plurality of flexible strands extend substantially perpendicular between the first ovoid ring and the second ovoid ring. 
     
     
       24. The artificial spinal disc of  claim 23 , wherein:
 the first ovoid ring has a first open interior; 
 the second ovoid ring has a second open interior; and 
 the artificial spinal disc further comprises a second grill structure extending across the second open interior.